Excess mortality was observed across all age groups except for those under 15

This heat wave, which occurred from June 17 to July 2, 2026, was exceptionally severe—its intensity even surpassing that of August 2003—and was also notable for its unprecedented early onset and duration. During this period, 92 departments were affected by the heat wave, representing 98.5% of the population of mainland France.

For the periods and departments affected by the heat wave, at least 5,764 excess deaths from all causes were estimated, representing an increase of more than 36%. More than half (56%) of the excess deaths occurred between June 25 and 27.

An unprecedented excess mortality from all causes was observed across all age groups aged 15 and older, with a marked increase in deaths among those aged 45 and older, highlighting the health impact associated with the remarkable intensity and duration of the population’s exposure to heat. People aged 75 and older accounted for two-thirds of this preliminary toll, with at least 3,719 excess deaths (+33.3%).

Deaths from all causes observed during this heatwave increased across all types of locations of death: hospitals, homes, and nursing homes/retirement homes. 

Excess all-cause mortality is higher in regions where the population was most exposed to the heat

All regions experienced excess all-cause mortality, with the exception of Corsica, Occitanie, and Provence-Alpes-Côte-d’Azur, where the population was exposed to less intense heat between June 17 and July 2.

The region most affected by excess all-cause mortality is Île-de-France, with nearly 2,000 excess all-cause deaths (+81.2%). The other regions most affected are Grand-Est (635 excess deaths, +38.9%), Pays de la Loire (553 excess deaths, +55.2%), and Centre-Val-de-Loire (511 excess deaths, +62.6%).

A preliminary estimate to be finalized at the end of the summer monitoring period

Mortality data come from civil registry offices and are transmitted by INSEE. They are derived from a sample of approximately 5,000 municipalities, covering 84% of national mortality. These administrative data, which do not include information on medical causes of death, are digitized and extrapolated to estimate results at the national level.

There is a time lag between the occurrence of a death and its reporting to Santé publique France: on average over the course of a year, 50% of the data is available by Day 3, and nearly 95% by Day 10. This delay may be longer during specific periods (school breaks, holidays, long weekends, or epidemic peaks).

The information collected includes age and the type of location of death (home, nursing home/retirement home, hospital, etc.). This information is collected by the registrar at the time the death is reported to city hall and should be interpreted with caution, as there may be confusion between the individual’s home and a nursing home or retirement home.

To calculate excess risk during heat waves, the daily number of deaths is compared to an expected number, estimated using a statistical model adapted from the EuroMomo project. This model, used by 28 European countries, incorporates six years of historical data, the general trend, and seasonal fluctuations, while excluding periods of extreme events. It is applied at the departmental level, for all ages and by age group, but not by type of place of death.

The final estimate of excess mortality—consolidated for the entire summer and broken down by heat wave—will be presented in the summer report produced after the monitoring period.